1. Field of the Invention
The present invention relates generally to the data processing field and, more specifically, to a computer implemented method, apparatus and computer program product for building a runtime environment of a system containing a plurality of different versions of at least one software component.
2. Description of the Related Art
When an enterprise application server (EAS) in a production system is updated, most fix pack installation software will completely upgrade the enterprise application server as a whole. In particular, all the profiles or server runtimes are upgraded to the latest fix pack version, and they will all run at the same enterprise application server fix pack level. There are no provisions to install and maintain different fix pack versions in the same machine.
Assume, for example, that an enterprise application server base version, for example, an IBM WebSphere® Application Server (WAS) version 6.1, is being installed on a system. Assume also that three different runtime environments (REs), for example, WAS profiles X, Y and Z, exist on the enterprise application server, and that there are also three different applications: deployed on the X, Y and Z profiles, for example, TEST1 on profile X, TEST2 on profile Y, and TEST3 on profile Z. Assume also that it is it required to upgrade the EAS from one version to another, for example, from WAS version 6.1 to WAS version 6.1.0.25, only for application TEST2 deployed on runtime environment Y, and that it is not required to upgrade the EAS for the other applications. The upgrade, in fact, might even have a negative impact to one or both of applications TEST1 and TEST3. For example, application TEST1 may have been developed specifically to use the interface provided by IBM WebSphere® Application Server version 6.1.
Current patch upgrades for enterprise applications generally upgrade the complete enterprise application server. There are no provisions to upgrade only one or more particular runtime environments of an enterprise application server so that different runtime environments can run at different fix pack levels which are relevant to the applications deployed on the runtime environments. Current runtime environments also require that the base enterprise application server be running and completely rely on the base enterprise application server files. They do not have an option of selecting the version of interest, for example, profile X, which exists on system s1 may want to run on IBM WebSphere® Application Server 6.1, whereas profile Y on the same system s1 may want to run on IBM WebSphere® Application Server 6.1.5.